// 按钮
.btn (@w, @h: @w, @r: 0, @c: @c-btn, @time: 1s, @d: 5%, @l: 70%) {
  .pos-r;
  .of-h;
  .box>.radius(@r, @w, @h);
  .bgc(@c);
  .font-cc(@h);
  .cur-p;
  .transition(all, @time, 0s, ease-in-out);
  &:after {
    .con("");
    .absolute;
    .d-b;
    .box>.radius(@r, 100%, @h);
    .bg-radial(circle, lighten(@c, @l) 10%, @c-t 11%);
    .bgr(no-repeat);
    .bgp(50%);
    .op(0);
    .scale(10, 10);
    pointer-events: none;
    .transition(all, @time, 0s, ease-out);
  }
  &:hover {
    .bgc(darken(@c, @d));
    .transition(all, @time, 0s, ease-in-out);
  }
  &:active:after {
    .op(0.4);
    .scale;
    .transition(all, 0s, 0s, ease-out);
  }
}
